Scientists have developed low-cost spray-on solar cells that could result in a dramatic drop in the price of solar electricity.
Designed to be applied using a method similar to car paint, the cells could be easily mass produced, giving solar power the chance of ubiquity. The spray technique also results in very little waste, which helps to keep manufacturing costs low.
If the technique takes off we could see solar cells built into everything from cars to clothes, leading to a move away from centralised power generation.
The cells are made from a rival material to market-dominating silicon: perovskite. Although only recently adopted for use in solar cells, the material is gaining popularity due its low price and energy costs.
“There is a lot of excitement around perovskite-based photovoltaics,” explained Professor David Lidzey, lead researcher from The University of Sheffield Department of Physics and Astronomy.
“Remarkably, this class of material offers the potential to combine the high performance of mature solar cell technologies with the low embedded energy costs of production of organic photovoltaics.”
The design of the cells is similar to organic equivalents, but with better performance.
“What we have done is replace the key light absorbing layer – the organic layer – with a spray-painted perovskite,” explained Lidzey. “Using a perovskite absorber instead of an organic absorber gives a significant boost in terms of efficiency.”
Although not quite as high as silicon, the efficiency levels of perovskite cells are far better than their organic counterparts.
“The best certified efficiencies from organic solar cells are around 10%,” said Lidzey.
“Perovskite cells now have efficiencies of up to 19%. This is not so far behind that of silicon at 25% – the material that dominates the worldwide solar market.”
At present the team have only achieved 11% efficiency but believe that with further research this can be improved.
The study itself, however, has moved ultra-thin solar cell technology far closer to mass production.
“This study advances existing work where the perovskite layer has been deposited from solution using laboratory-scale techniques,” said Lidzey.
“It’s a significant step towards efficient, low-cost solar cell devices made using high volume roll-to-roll processing methods.”
Lidzey argued that this solar technology would become increasingly key in power generation.
“I believe that new thin-film photovoltaic technologies are going to have an important role to play in driving the uptake of solar-energy, and that perovskite-based cells are emerging as likely thin-film candidates,” he said.
Images courtesy of Alex Barrows, Lucy Pickford and Jon Griffin via The University of Sheffield.